drm/i915: Remove unused/wrong INF_UNIT_LEVEL_CLKGATE

INF_UNIT_LEVEL_CLKGATE is not replicated, but since it's not actually
used it can just be removed.
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230206165410.3056073-2-lucas.demarchi@intel.com

drivers/gpu/drm/i915/gt/intel_gt_regs.h

@@ -769,9 +769,6 @@
 #define GEN10_DFR_RATIO_EN_AND_CHICKEN		MCR_REG(0x9550)
 #define   DFR_DISABLE				(1 << 9)
 
-#define INF_UNIT_LEVEL_CLKGATE			MCR_REG(0x9560)
-#define   CGPSF_CLKGATE_DIS			(1 << 3)
-
 #define MICRO_BP0_0				_MMIO(0x9800)
 #define MICRO_BP0_2				_MMIO(0x9804)
 #define MICRO_BP0_1				_MMIO(0x9808)